'I must relate that I've never met a person whose intellect I respected or whose philosophical learning was more than amateur -- that I never knew such a person to take Nietzsche seriously.'

Hmmm, you ask me about the dash and the "that" conjunction, and whether the grammar is correct - now you're gonna hit me with symantics? Is that nice?

'A person' in the first phrase refers to 'such a person' from the second one, and not to Nietzsche, right?

"A person" and "such a person" refer indirectly to "any one among all the people I have met," not to Nietzche.I indirectly make three disparaging statments about all the people I have met:(1) none has an intellect which I respect(2) none has a philosophical learning beyond amateur(3) none has been known by me to take Nietzche seriously"Such a person" means "such a person as I have met."

You know, you may have a point there. I wonder if prior context would reveal the first part to be a Nietzsche quote and the second part to be a humorous retort?CJ has a Nietzsche quote on his avatar. I wonder if they ever met? Well, I guess not. He died a year before I was born.

I also don't find the sentence satisfactory, but I think (although I could be way off base) that the author meant "[any person I've ever met who falls into the category of being intellectual and having more than an amateur understanding] didn't take Nietzsche seriously."

What he wrote was that he never met anyone who fell into that category at all. It would take a pretty conceited person to think he'd never met such a person, wouldn't it?